Large scale rear-projection-screens on both sides of the viewer make up an alley.
One sees a rectangle in black and white, whose dimensions match the aspect ratio of the projection-screen. At first, only a point in the middle of one of the screens is visible, which slowly grows. The size of the now recognizable rectangle increases exponentially, so that the viewer gets the impression of a spatial depth, from which the rectangle flies towards him with growing speed. At the moment that the rectangle reaches its maximum, screen-filling size, it flips over to the other side at maximum speed - seemingly pervading the real space between the screens - and reduces speed and size at the same rate as the former increase. It slowly shrinks to the initial point, only to loop back and recommence the process.
The visual experience is accompanied by a sine-wave, which increases or decreases in volume at the same rate as the rectangle size on each side of the projection screen. While the sound is hardly audible when the rectangle is at its state of point-size, it reaches its maximum volume as the rectangle reaches its full size, flipping over to the other side in synchronization with the rectangle.